ZURICH—Sepp Blatter, the president of soccer’s world governing body, will officially leave his post of nearly 18 years when FIFA elects his successor on Feb. 26, he announced on Monday.

Mr. Blatter called in June for a new election following the disclosure of U.S. and Swiss investigations into massive corruption by FIFA executives spanning several decades. His intentions since then have been the subject of ample speculation, with people close to him saying he would seek a sixth term in office.